The complex genetic nature of what makes some people more susceptible than others to tuberculosis (TB) may finally be revealing itself. The answer may lie in the genes that control cell-mediated immunity specifically a newly discovered gene that governs how macrophages cope with infectious organisms such as Mycobacterium tuberculosis. The discovery sheds new light on the molecular basis of the pathogenesis of TB a disease that kills more than 2million people each year. (excerpt)